Allergic Reaction to Hemp Seed or Oil: Causes, Symptoms and Treatment

If you have allergies - food, environmental or otherwise - you know the struggle. Watery eyes, stuffy nose, sneezing, itchy skin and the list goes on. Unfortunately for a very small group of people, hemp is the culprit that causes all of those uncomfortable symptoms. 

One of my friends has suffered the congestion from seasonal allergies for years from grass in the spring and ragweed pollen in the fall. More recently her body decided to keep things interesting by adding a skin reaction as well.  She woke up one morning to an itchy rash that covered most of her body.  We began a fun (and by fun, I mean tedious) game of elimination to figure out the culprit. Sadly the cause was hemp! 

One in six people suffer from some type of allergy.  Reactions can range from mild to severe and potentially life threatening.  Very few people have an allergy to hemp, but let's take a deeper look at the topic.

What is a hemp allergy?

A hemp allergy is an autoimmune response in the body after hemp is consumed or inhaled.  Your immune system views hemp as a foreign substance or “intruder”. Despite it being harmless in most other people, your body reacts and launches a defense attack. This is the process that takes place with all allergic reactions.

Your immune system produces antibodies which attach themselves to mast cells.  A mast cell is a type of white blood cell found throughout your body.  Those mast cells then release what is called histamines.  It’s the histamines that cause those pesky symptoms like swelling, itchiness and redness - or what we call, "allergic reactions".

Picture a castle being invaded by marauders.  The inhabitants of the castle defend themselves by sending their knights to the ramparts and firing arrows and cannons.  This is your body attempting to fight off the “attack of the hemp allergens”.  Unfortunately for us, the body’s attempt to fight the invader brings with it uncomfortable symptoms. 

What are the most common allergens?

Although you can develop an allergy to almost anything, it’s usually a pollen or a protein.  A pollen is inhaled which causes the release of histamines in the nose.  Your body’s response is sneezing, and an itchy runny nose and watery eyes.  The most common environmental culprits are the seasonal pollens like ragweed and grass.  Dust mites and pet dander are other inhaled allergens.  These however, are not caused by pollen but rather protein.  

Protein is shed by the animal through their skin, fur and waste in tiny amounts that we then inhale.  In fact, “approximately 80% of allergy sufferers are allergic to proteins that are found in the waste and decomposed body parts of dust mites” –  Ewww! Did anyone else just shudder and have the urge to immediately vacuum their carpets and wash their bedding? 

It’s possible to also trigger an allergic response by ingesting the protein. This is the reason why people are typically allergic to high protein foods such as peanuts or eggs.  

Inhaled allergens produce a reaction in the nose, eyes, and throat.  More severe reactions can impact the lining of the lungs making breathing difficult.  Ingesting an allergen can affect the stomach and bowel.  Skin reactions can be triggered by both inhaled and ingested allergens as well as topical absorption.  

What causes an allergic reaction to hemp?

Hemp is consumed as food

Hemp or Cannabis sativa, is a hardy, multi-use plant.  It’s seeds, roots and leaves are edible.  But since hemp is a high protein food, it can cause an allergic response in the body, just like eggs and peanuts.  Hemp seeds contain over 30 g of protein in a 100g serving.   

The hemp plant produces pollen

    Hemp is extremely robust and hardy. An individual hemp flower can produce over 350,000 pollen grains and one hemp plant can produce hundreds of these flowers.  The wind can carry that pollen over 40 kilometres and cause airborne exposure resulting in the same symptoms as a ragweed allergy.


    Hemp can be used topically

    The oil that is extracted from hemp seeds is cold pressed and used as an ingredient in skincare.  Hemp seed oil is an emollient which means it is absorbed into the skin and makes an excellent moisturizer. It also has anti-inflammatory as well as antibacterial properties.  I’ll talk more about hemp seed oil and it’s potential as an allergen later.

    pro-aging serum with hemp seed oil


    What are the reactions and common symptoms of a hemp allergy?

    Since it’s pollen or protein that causes the allergic reaction, you can develop symptoms by ingesting hemp (in particular the high protein seeds) or by inhaling hemp pollen.  The reactions to inhaling hemp pollen may include:

    • Swelling and itchy skin
    • Itchy throat
    • Sneezing
    • Cough
    • Nasal congestion
    • Conjunctivitis (pink eye)
    • Difficulty breathing (in more severe reactions)

    And as with any allergen, the symptoms of exposure to hemp and its pollen/protein are varied.  They can range from mild to severe depending on how your body reacts but include:

    • Irritation: itchiness, swelling, and puffiness of the eyes, and the skin in general.
    • Hives: in the forms of skin rash, plaques, or pale red bumps
    • Allergic Rhinitis: sneezing, running nose, and nasal congestion
    • Asthma: difficulty in breathing, tightness in the chest, and abnormal lung function.
    • Conjunctivitis: pink and/or red bloodshot eyes.
    • Anaphylaxis: skin rash, nausea, vomiting, difficulty in breathing, and shock. This is the most severe allergic reaction a person can have and they should seek medical attention immediately.

    Thankfully severe reactions are rare but it makes us ask the question:

    Who is most likely to develop a hemp allergy?

    Anyone who is allergic to dust mites, mould, and cat dander has a higher probability of developing hemp or cannabis allergies.  These are the “big three” of common allergens and those who are sensitive to any or all of them are at risk of also having a sensitivity to hemp.  Also, people with peanut, egg or dairy allergies should be cautious when ingesting hemp for the first time.  

    What parts of the hemp plant are most allergic?

    Although any part of the hemp plant can trigger an allergic reaction, as I said earlier, the part that contains the highest amount of protein or pollen tends to be the culprit.  This includes hemp hearts (which are shelled hemp seeds) powder and by-products such as hemp milk.  

    Can hemp seeds upset your stomach?

    Ingesting hemp seeds can be extremely beneficial for your health.  In addition to being high in protein and healthy fats, they contain a large amount of an amino acid called arginine.  Arginine produces nitric oxide in your blood which allows blood vessels to relax and dilate, lowering your blood pressure.

    They also help skin conditions like eczema since they are rich in essential fatty acids.  

    Hemp is also a good source of fibre, both soluble and insoluble.  This aids your digestive system and helps to regulate your cholesterol levels.  

    It’s also important to make sure that any hemp seed product you purchase uses pure hemp that has been grown and harvested under strict environmental standards.  Hemp is a bioaccumulator, meaning it absorbs almost everything from the soil including heavy metals and chemical waste.  Any hemp grown for human use, whether for consumption or topical applications must be toxin free.  If you don’t choose high quality hemp products, you could develop an upset stomach from the contaminants the hemp has absorbed while it was growing.

    Also, hemp seeds should be eaten in moderation.  The high fat and fibre content can also cause digestive issues such as bloating, nausea and constipation.  It’s always a good idea to drink water when consuming hemp seeds to aid in digestion. 

    How do I test for an allergic reaction?

    Testing for both pollen and protein allergies are essentially the same.  An allergist will perform either a skin prick test or a patch test.  They take a tiny amount of the potential allergens and either scratch the surface of the skin or place it on a disc and tape it to your back. If you’ve had this done you know why they choose to place the patches on your back. It’s harder to reach the offending patch and scratch it off!  

    Reactions to common allergens such as pets and pollen are immediate however skin allergies are not.  It can take anywhere from 24-48 hours for a reaction to appear and can last for two to three weeks.  That’s what makes pinpointing a skin allergy at home so difficult.  It’s often a process of elimination and backtracking to recall any new products you may have been in contact with.

    If you’ve purchased a new product and are unsure if it will cause an allergic reaction, it’s a good idea to do a home version of the patch test.  Put a small amount on your skin and wait at least 24 hours.  Should any redness or itching occur, discontinue use immediately.  

    Can hemp seed oil cause an allergic reaction?

    Remember I said that you could be allergic to any part of the hemp plant but the areas with the highest concentration of protein or pollen are the most likely?   Well here is what is interesting.  Since hemp seed oil is refined to be 100% fat, it is less likely to cause an allergic reaction.  This is true if the oil is ingested or used topically.  

    It’s still possible to develop an allergic reaction to hemp seed oil but it’s not as common.

    How to treat a hemp allergy?

    How you treat your hemp allergic reaction will depend on your symptoms.  Prescription as well as over the counter medications such as antihistamines and corticosteroid inhalers will provide relief from the runny nose, sneezing and itching symptoms.  If your reaction is from touching or applying a hemp product to your skin, topical steroid creams may be helpful or even a natural remedy such as ice packs.  

    Alternatives to hemp

    If you have determined that you suffer from an allergy to hemp or its by-products you may want to switch to an alternative.  Flax, chia and pepitas (pumpkin seeds) are all excellent substitutes to hemp seed and hemp hearts.  


    Pumpkin Seeds

    Flax seed oil can be substituted for hemp seed oil in recipes and cooking.  Argan oil can also be used as an alternative carrier oil to hemp for skincare products.  

    In summary

    As with any plant or herb, hemp (Cannabis sativa) can cause an allergic reaction.  Those who are prone to seasonal allergies and plant-based protein allergies are more susceptible.  Both the pollen and the protein in hemp can produce symptoms ranging in severity from mild to severe.  

    It’s important to look for companies that choose high quality hemp products to reduce the chance of contamination from chemicals in the soil where it is grown.  

    At empyri, we make sure that all raw materials are ethically sourced, legal and receive a certificate of analysis ensuring they are heavy metal free.  You can be confident that our hemp-based products, including our enriching soaps, as well as all empyri ingredients are also ethically sourced, non-GMO, solvent free, cruelty free and vegan.


    Jennifer Grant with Hemp Roots


    Author Bio: Jennifer is the president and founder of empyri.  Jennifer’s passion for formulation and product development was set ablaze in 2019, when she incorporated the healing power of cannabis roots into her long-standing three-step skin care system. Armed with scientific evidence on the actives in cannabis roots and seeds, a clean and conscious brand was born. Using her masters degree in bio-chemical engineering, Jennifer is forging a path to ...READ FULL BIO